430 RESEARCH IN CHINA. 
Banded cherty marble, No. 102.—This represents merely another phase 
of the last, and it was obtained at the same outcrop. 
Finely laminated brown and reddish bands alternate with white hema- 
titic layers much as in No. 100. The darkest lamine weather out in relief 
because of their siliceous composition; while the gray and red layers are 
more easily dissolved. As viewed in thin section these cherty and calcare- 
ous bands intergrade without demarkation. The whole rock has an obscure 
parallel structure which is emphasized by the streaks of iron-ore granules 
which give color to the dark layers. Much of this parallelism may be 
ascribed to stratification in the original limestone, but the deformation has 
also been a notable factor. 
Pink and green amphibolite, No. 85.—This is a rock of unusual appear- 
ance which is associated with the lowest members of the Shi-tsui series 
southeast of the village of that name. Layers of considerable thickness are 
interbedded with biotite schist and lie beneath the quartzite on the east 
tributary of the T’ai-shan-ho (Fig. 20, stratum 6). Its relations to the 
section, as well as its mineral composition, indicate that it is a metamor- 
phosed limestone. 
The attention of the geologist is at once attracted by the peculiar 
color of this amphibolite. Most of the rock is composed of light-green 
actinolite needles, but pink calcite is interspersed in many irregular blotches. 
The structure is massive, as in a marble, and neither banding nor cleavage 
is observable. 
The little needles of actinolite are disposed in radiating bunches in a 
ground-mass of quartz and calcite, with subordinate feldspar. Near the 
centers of these rosettes biotite usually occurs in large ragged flakes (Plate 
LVII, Fig. A). The biotite flakes cut directly through the actinolite fibers 
after the manner of tertiary porphyritic* minerals developed under mass- 
static conditions. Many of the fibers have been absorbed without change 
during the growth of the biotite. 
Gneissic amphibolite, No. 90.—A thick bed of this amphibolite is 
included in the schistose sediments in the canyon of the T’ai-shan-ho above 
Shi-tsui (Plate XVIII, stratum15). In the field its relations are those of a 
conformably bedded member of the Shi-tsui series. 
A faintly banded massive rock consisting of a light-gray ground-mass 
in which are set long prisms of blackish-green hornblende. ‘This network 
of amphiboles bears little relation to the gneissic banding. ‘The crystals 
are promiscuously oriented. 

* Word used in the sense of megascopic crystals in an aphanitic schist (Van Hise: A Treatise on Meta- 
morphism, p. 699. 
